package com.hucheng.common.utils;

import java.io.ByteArrayOutputStream;
import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.security.InvalidKeyException;
import java.security.Key;
import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.NoSuchAlgorithmException;
import java.security.PrivateKey;
import java.security.PublicKey;
import java.security.Signature;
import java.security.SignatureException;
import java.security.cert.Certificate;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.HashMap;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.Map;

import javax.crypto.Cipher;

import com.alibaba.fastjson.JSONObject;
import org.apache.commons.codec.binary.Base64;

/**
 * <p>RSA签名,加解密处理核心文件，注意：密钥长度1024</p>
 *
 * @author leelun
 * @version $Id: RSA.java, v 0.1 2013-11-15 下午2:33:53 lilun Exp $
 */
public class RSAUtils {

    private static final String pubKey = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQC2HL0Wr+F2JkD2TZOoB0kJW9onz0HL52zjhIZxXKO71b72XEtMRujAxu0jZneHfKdST55t3wZ9xLgx21kTqMB9q/RtCq4x5HT/0cTCCae/i4wwi484hsG/SYynLAdZbV4GEiqQ0HZU/aPPenLe7NY0+5N2Bg8KqseKFdWPzaccxQIDAQAB";

    private static final String priKey = "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";


    /**
     * 签名算法
     */
    public static final String SIGNATURE_ALGORITHM = "SHA1withRSA";
    /**
     * 加密算法RSA
     */
    public static final String KEY_ALGORITHM = "RSA";
    /**
     * RSA最大加密明文大小
     */
    private static final int MAX_ENCRYPT_BLOCK = 117;

    /**
     * RSA最大解密密文大小
     */
    private static final int MAX_DECRYPT_BLOCK = 128;

    /**
     * 获取公钥的key
     */
    private static final String PUBLIC_KEY = "RSAPublicKey";

    /**
     * 获取私钥的key
     */
    private static final String PRIVATE_KEY = "RSAPrivateKey";

    /**
     * <p>
     * 生成密钥对(公钥和私钥)
     * </p>
     *
     * @return
     * @throws Exception
     */
    public static Map<String, Object> genKeyPair() throws Exception {
        KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(KEY_ALGORITHM);
        keyPairGen.initialize(1024);
        KeyPair keyPair = keyPairGen.generateKeyPair();
        RSAPublicKey publicKey = (RSAPublicKey) keyPair.getPublic();
        RSAPrivateKey privateKey = (RSAPrivateKey) keyPair.getPrivate();
        Map<String, Object> keyMap = new HashMap<String, Object>(2);
        keyMap.put(PUBLIC_KEY, publicKey);
        keyMap.put(PRIVATE_KEY, privateKey);
        return keyMap;

    }

    public static void main(String[] args) throws Exception {
        Map<String, Object> genKeyPair = genKeyPair();

//        String base64publicKey = getPublicKey(genKeyPair);
//        System.out.println("公钥 \n" + base64publicKey);
//        String base64privateKey = getPrivateKey(genKeyPair);
//        System.out.println("私钥\n" + base64privateKey);

        System.out.println("公钥 \n" + pubKey);
        System.out.println("私钥\n" + priKey);

        String passwd = "cat123113";
        String charsetName = "utf-8";

        Map<String, Object> maps = new LinkedHashMap<>();
        maps.put("Content-Type", "application/json");
        maps.put("action", "user_defaultAccessId");
        maps.put("accessId", "");
        maps.put("format", "json");
        maps.put("userId", "0");
        JSONObject json = new JSONObject();

        maps.put("reqObject", json);

        String params = getParams(maps);
        System.out.println("Content-Type=application%2Fjson&action=user_defaultAccessId&accessId=&format=json&userId=0&reqObject=%7B%7D");

        String encryptByPublicKey = Base64.encodeBase64String((encryptByPublicKey(
                params.getBytes(charsetName), pubKey)));
        System.out.println("加密\n" + encryptByPublicKey);

        byte[] decryptByPrivateKey = decryptByPrivateKey(Base64.decodeBase64(encryptByPublicKey),
                priKey);
        String string = new String(decryptByPrivateKey, "utf-8");
        System.out.println("解密后\n" + string);

        String sign = sign(encryptByPublicKey, priKey, "utf-8");
        System.out.println(sign);

        boolean verify = verify(encryptByPublicKey, sign, pubKey, "utf-8");
        System.out.println(verify);
    }

    public static String getParams(Map<String, Object> maps) throws UnsupportedEncodingException {
        StringBuilder param = new StringBuilder();
        for (Iterator<Map.Entry<String, Object>> it = maps.entrySet().iterator(); it.hasNext(); ) {
            Map.Entry<String, Object> e = it.next();
            if (e.getKey() == "reqObject") {
                param.append("&").append(e.getKey()).append("=").append(URLEncoder.encode(e.getValue().toString().replaceAll(" ", ""), "UTF-8"));
            }else{
                param.append("&").append(e.getKey()).append("=").append(URLEncoder.encode(e.getValue().toString(), "UTF-8"));
            }
        }
        return param.toString().substring(1).replaceAll("\\+", "%20");
    }

    /**
     * 签名字符串
     *
     * @param text       需要签名的字符串
     * @param privateKey 私钥(BASE64编码)
     * @param charset    编码格式
     * @return 签名结果(BASE64编码)
     */
    public static String sign(String text, String privateKey, String charset) throws Exception {

        byte[] keyBytes = Base64.decodeBase64(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PrivateKey privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initSign(privateK);
        signature.update(getContentBytes(text, charset));
        byte[] result = signature.sign();
        return Base64.encodeBase64String(result);

    }

    public static String sign(String text, PrivateKey privateKey, String charset)
            throws SignatureException,
            InvalidKeyException {
        try {
            Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
            signature.initSign(privateKey);
            signature.update(getContentBytes(text, charset));
            byte[] result = signature.sign();
            return Base64.encodeBase64String(result);
        } catch (NoSuchAlgorithmException e) {
            //不可能发生，
            return null;
        }
    }

    /**
     * 签名字符串
     *
     * @param text      需要签名的字符串
     * @param sign      客户签名结果
     * @param publicKey 公钥(BASE64编码)
     * @param charset   编码格式
     * @return 验签结果
     */
    public static boolean verify(String text, String sign, String publicKey, String charset)
            throws Exception {
        byte[] keyBytes = Base64.decodeBase64(publicKey);
        X509EncodedKeySpec keySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        PublicKey publicK = keyFactory.generatePublic(keySpec);
        Signature signature = Signature.getInstance(SIGNATURE_ALGORITHM);
        signature.initVerify(publicK);
        signature.update(getContentBytes(text, charset));
        return signature.verify(Base64.decodeBase64(sign));

    }

    /**
     * <P>
     * 私钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param privateKey    私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPrivateKey(byte[] encryptedData, String privateKey)
            throws Exception {
        byte[] keyBytes = Base64.decodeBase64(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, privateK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;

    }

    /**
     * <p>
     * 公钥解密
     * </p>
     *
     * @param encryptedData 已加密数据
     * @param publicKey     公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] decryptByPublicKey(byte[] encryptedData, String publicKey)
            throws Exception {
        byte[] keyBytes = Base64.decodeBase64(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.DECRYPT_MODE, publicK);
        int inputLen = encryptedData.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段解密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_DECRYPT_BLOCK) {
                cache = cipher.doFinal(encryptedData, offSet, MAX_DECRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(encryptedData, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_DECRYPT_BLOCK;
        }
        byte[] decryptedData = out.toByteArray();
        out.close();
        return decryptedData;

    }

    /**
     * <p>
     * 公钥加密
     * </p>
     *
     * @param data      源数据
     * @param publicKey 公钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(byte[] data, String publicKey) throws Exception {
        byte[] keyBytes = Base64.decodeBase64(publicKey);
        X509EncodedKeySpec x509KeySpec = new X509EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key publicK = keyFactory.generatePublic(x509KeySpec);
        // 对数据加密
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, publicK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;

    }

    /**
     * <p>
     * 公钥加密
     * </p>
     *
     * @param data 源数据
     * @param cert 证书
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPublicKey(byte[] data, Certificate cert) throws Exception {

        // 对数据加密
        PublicKey uk = cert.getPublicKey();
        Cipher cipher = Cipher.getInstance(uk.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, uk);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;

    }

    /**
     * <p>
     * 私钥加密
     * </p>
     *
     * @param data       源数据
     * @param privateKey 私钥(BASE64编码)
     * @return
     * @throws Exception
     */
    public static byte[] encryptByPrivateKey(byte[] data, String privateKey) throws Exception {
        byte[] keyBytes = Base64.decodeBase64(privateKey);
        PKCS8EncodedKeySpec pkcs8KeySpec = new PKCS8EncodedKeySpec(keyBytes);
        KeyFactory keyFactory = KeyFactory.getInstance(KEY_ALGORITHM);
        Key privateK = keyFactory.generatePrivate(pkcs8KeySpec);
        Cipher cipher = Cipher.getInstance(keyFactory.getAlgorithm());
        cipher.init(Cipher.ENCRYPT_MODE, privateK);
        int inputLen = data.length;
        ByteArrayOutputStream out = new ByteArrayOutputStream();
        int offSet = 0;
        byte[] cache;
        int i = 0;
        // 对数据分段加密
        while (inputLen - offSet > 0) {
            if (inputLen - offSet > MAX_ENCRYPT_BLOCK) {
                cache = cipher.doFinal(data, offSet, MAX_ENCRYPT_BLOCK);
            } else {
                cache = cipher.doFinal(data, offSet, inputLen - offSet);
            }
            out.write(cache, 0, cache.length);
            i++;
            offSet = i * MAX_ENCRYPT_BLOCK;
        }
        byte[] encryptedData = out.toByteArray();
        out.close();
        return encryptedData;

    }

    /**
     * @param content
     * @param charset
     * @return
     * @throws SignatureException
     * @throws UnsupportedEncodingException
     */
    private static byte[] getContentBytes(String content, String charset) {
        if (charset == null || "".equals(charset)) {
            return content.getBytes();
        }
        try {
            return content.getBytes(charset);
        } catch (UnsupportedEncodingException e) {
            throw new RuntimeException("签名过程中出现错误,指定的编码集不对,您目前指定的编码集是:" + charset);
        }
    }

    /**
     * <p>
     * 获取私钥
     * </p>
     *
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPrivateKey(Map<String, Object> keyMap) throws Exception {
        Key key = (Key) keyMap.get(PRIVATE_KEY);
        return Base64.encodeBase64String(key.getEncoded());
    }

    /**
     * <p>
     * 获取公钥
     * </p>
     *
     * @param keyMap 密钥对
     * @return
     * @throws Exception
     */
    public static String getPublicKey(Map<String, Object> keyMap) throws Exception {
        Key key = (Key) keyMap.get(PUBLIC_KEY);
        return Base64.encodeBase64String(key.getEncoded());
    }
}
